massoutage

MassOutage API

A free, open-CORS JSON API for US power outages: live county status, municipalities, incidents and threshold alerts, plus a decade of history.

Unofficial aggregate of public utility and government data; confirm with the utility or your OEM before acting. Emergencies: call 911.

Access

Free to use. Browser apps call any endpoint directly with no key (CORS *). Data is CC BY 4.0: credit “MassOutage (massoutage.com)” and link back.

Public API access is rate-limited to protect the service from abuse.

MassOutage has grown — 1.6M requests from 437K distinct clients in the last 30 days. To keep it reliable and stop spam/abuse, unauthenticated use is capped. A free accountlifts the limit substantially — still free, no payment. Your site’s own widgets are unaffected.

Create a free account for higher limits →

Quick start

Base URL https://massoutage.com; counties by 5-digit FIPS (Monmouth County, NJ = 34025). Full list in the reference and OpenAPI spec.

County profile
curl -s https://massoutage.com/api/v1/counties/34025
Live county status
curl -s https://massoutage.com/api/v1/live/counties/34025
Larger incidents as GeoJSON
curl -s "https://massoutage.com/api/v1/live/counties/34025/incidents?min_customers=100&format=geojson"
Threshold alerts
curl -s "https://massoutage.com/api/v1/live/counties/34025/alerts?min_customers=1000&min_pct=5"

Versioning

Current version v1 (X-API-Version: 1), additive-only: fields are never renamed or removed, so ignore unknown ones. Breaking changes ship under /api/v2with 90 days’ notice.

Freshness

Live data refreshes ~every 10 min; poll no faster than every 5. Trust as_of / updated_at over your clock, and treat anything older than 30 min as stale.

Formats

JSON everywhere ({ data, meta? }). ?format=csv and geojson on the geographic endpoints; branded PNG charts under /chart.

Errors

JSON { "error" } with an HTTP status (400 bad input, 404 unknown, 500 server). Quote X-Request-Id when reporting one.

Status, coverage & AI

/api/v1/live/sourcesreports each source’s health and how many customers we see (also on the coverage page); a utility with no feed is never “all clear”. Building with an LLM? The AI guide is a copy-paste briefing of endpoints and rules.